Thursday, March 22, 2012

What I learned in med school 6: Diving reflex

Baby holding breath under water

Man experiencing cold water shock

Hey guys! I learned something very interesting today called the diving reflex. Basically, exposure to cold water around your nose and facial region triggers apnea (cessation of breathing) and bradycardia (slow heart rate). This is a reflex meant to protect us from aspiration of water during the initial stages of drowning. During this time, most of the blood flow is diverted to the brain, heart, and lungs until we resume breathing again.
This phenomenon is what makes babies hold their breaths and open their eyes when they are submerged in water. These babies above look like they know what they're doing under water but I'm sorry to say that it's a natural protective reflex! But they still look cute either way. Ciao until next time.

Pictures courtesy of: and Reuters

Tuesday, March 13, 2012

What I learned in med school 5: One bronchus is more vertical

Up until today, I had thought that if I accidentally inhaled or chocked on a small pea or a loose tooth, it would go down my trachea and by chance, it would either end up lodged in my left or right bronchus- with 50-50 chance of its final destination.
Well I was wrong! It turns out, as the left and right bronchi branch into the lungs from the trachea, one is more vertical than the other, and therefore would be the more likely one to receive these unwanted objects... would you like to guess which one?
Hope you had the right answer - The right bronchus descends more vertically and the left bronchus has a more horizontal structure- which means, if you inhale something by accident, it would go down your trachea and have a much greater chance of going straight down into the right bronchi rather than taking that horizontal turn to the left! Gravity is on it's side on its way to the right.

picture courtesy of:

Friday, March 9, 2012

What I learned in med school 4: A pink flower can save your life

This flower is called digitalis. It's pretty, colorful, looks feminine, and it may save your life if you have heart failure and various other heart conditions. This pretty little thing is used to prepare a drug called digoxin. This medication increases the calcium concentration inside your heart cells (myocytes). Increasing the calcium in your myocytes leads to a greater force of contraction. This can be beneficial in situations where the heart can not produce enough force to pump blood to the rest of your body. And we all know the dangers of not getting enough blood supply to our body, which is also known as ischemia - it leads to tissue death. This can be life threatening.
So my conclusion, for a hurting or failing heart, in reality or figuratively speaking, pink flowers can literally and metaphorically make things feel better.

Picture courtesy of

Friday, March 2, 2012

What I learned in med school 3: Split brain syndrome

In split brain syndrome, a callosotomy is performed. In the previous post, I discussed the corpus callosum and how it is the bridge between our two hemispheres. This is a great thing because our two brains can communicate and work together. But in patients with epilepsy, it could be a bad thing because it facilitates the spread of the seizures from one hemisphere to the other. The callosotomy, which is a last resort procedure, interrupts or reduces these spreads of brain activity and therefore, the symptoms of the seizures.
Even though split brain patients are able to lead normal lives, the side effects of this procedure are very interesting because you essentially have two brains not talking to each other or partially ignoring each other. Sometimes, patients speak out loud what they want to communicate to the other side of the brain. Patients are unable to use just the right eye and read something because the speech center is located in the left hemisphere. These are just a couple of examples but each patient is unique and may manifest different side effects.

Picture courtesy of